Power transmission



Jan. 25, 1949.

E. c. MAXWELL 2,459,829

POWER TRANSMISSION Filed April 29, 1946 s LENOID s4 37 l2 H 57 SOLENOID I \DIFFERENTIAL 24 3O 26 w GENERATOR awe/rm EDWARD C; MAXWELL Patented Jan. 25, 1949 2 459329 UNITED STATES PATENT QFFICE POWER TRANSMISSION Edward C. Maxwell, United States Navy Application April 29, 1946, Serial No. 665,711

8 Claims. (Cl. 172-284) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates to transmission devices the medium of this shaft is and a solenoid operaand more particularly to power transmission deted clutch is there is driven one shaft ll of a vices wherein power from a prime mover may be difierential member is. The clutch i5 is ordiconnected either through electrical torque narily kept in engaging position by means of a mechanism or directly so as to drive a load as 5 coiled spring Iii. desired. The driven member such, for example, as the Heretofore many methods have been proposed rear wheels of an automobile may be driven for the transmission of power through shafting, through a suitable driven torque tube 19, or the and wherein so-called electromagnetic clutches like, which may suitable universal joint have been employed to permit a desired amount if means (not shown). Driven torque tube is has of slippage between the relatively rotating parts keyed thereto a beveled gear 23 which meshes with and permit operation of a prime mover at a speed Coupling ear 2% keyed to a transversely extendwherein the moment of its torque is greatest. ing stub shaft 22 and by c mpa 0 beveled gears H eve ch prior de i h e a n be of 23 and 24 power is communicated to differential undesirable features, are frequently complicated shaft 25. The shaft 25 forms one of the diilerenand inherently unsatisfactory, and frequently tial extensions. A generator drive shaft exprove to be insufliciently flexible for the desired nd n fr m h fi r nt ins driv s th armature of a generator 2? to provide electric It i the purpose of the present inventi n t current. It will be apparent that with the torque provide a new and improved power transmission tube 19 stationary as when the rear wheels of an mechanism whereby a, desired degree of coupling automobile are stationary and With the differeneffect may be achieved between relatively rotattial shaft 25 stationary, rotation Of the drive shaft able parts so that a prime mover such, for eX- 0 t o h bevel e rs 2 and i3, clutch l5 and ample, as an internal combustion engine may be differential 58 Will rotate the shaft 26 and genoperated at speeds wherein maximum torque may ato 21 to generate an electric current. be provided, but the load to be driven can be As part of the electrical coupling mechanism operated at the desired low, intermediate or high there is provided a flywheel 28 which is directly speeds. rotated at a desired speed by the engine or other Another object of the present invention is to prime mover. This flywheel may include current provide a simple and reliable coupling mechanism 39 conducting coils 29 adapted to establish a magof the electrical type wherein an inductive field of netic field and in use electricity is c nducted from greater or lesser intensity as required is employed the generator 21 through wires 3d and 35 to inner to provide a variable drive for the driven members. and outer brushes 32 and 33 which engage corre- An additional object is to provide an electric spending slip rings 3d and Of course, any current supply which may vary in accord with suitable means may be employed to conduct the load conditions. electric current to the coils 29 and the current It. is a further object of the present invention to collecting arrangement shown is only illustrative. provide an automatic electrical drive and cou- As the prime mover rotates the generator faster pling arrangement which is operated upon atand. faster more and more ma netic field is creatainment of a desired speed to couple the prime iii ted by the increased current flowing through coils mover to the driven member in a direct fashion. 29. This causes the core to follow the rotation Other objects and advantages will be apparent of the flywheel 28.

from the following specification and accompa- The core 36 is supported upon one end of a tunying drawing, in which latter is illustrated a bular shaft 3'! which may be suitably mounted in schematic diagram of a construction embodying 45 bearings, and upon the opposite end may be a the present invention. spur gear The spur meshes with a Referring to the accompanying drawing, in the companion spur gear 39 mounted upon one end of embodiment illustrated there is provided a driva counter shaft 5i) and having at its opposite end ing shaft l0 having an end gear H by which it another spur gear ll. This latter gear 8! may be connected for rotation to a suitable prime meshes with a spur gear 42 mounted upon the mover (not shown), such for example as an inend of the driven torque tube 59. It will be apternal combustion engine. The shaft [0 has parent that the rotation of the core 35 induced keyed therein a beveled gear [2 through which by the increasing magnetic field compels rotapower may be communicated to a companion gear tion of sleeve 31 gears 38, 39, ll and 42 and drives 13 keyed to and rotating stub shaft [4. Through the tube I9.

As the speed of rotation of the driven torque 1 tube I9 increases it may drive a centrifugal switch device 33 at increasing speed until, at a predetermined speed such, for example, as 35 miles per hour, the centrifugal switch may be brought to close a circuit including battery 84 and wires 45 to energize solenoids 4! and 48 which are connected in parallel in the embodiment shown for simultaneous energization by the closing of the centrifugal switch 43.

Energizing solenoid 4'! draws solenoid core is to the left, in the direction of the arrow, and rotates lever to about fulcrum point '5l against the resistance of spring 52. The lower end of lever so may include a yoke, or other suitable arrangement, whereby spur gear 53 which is splined for axial movement along shaft in may be moved along the splined portion to a position whereby it engages with a companion spur gear mounted upon stub shaft 55 and, through another spur gear 5% meshing with gear -12, may drive t1 e torque tube It.

The above operation eifects a direct drivebetween the shaft iii to the driven member is through the medium of the gears 53, 5d, 55 and d2 as aforesaid.

Since the solenoid its is electrically connected in parallel with the solenoid 4'! it is simultaneously energized by the operation of the centrifugal switch to draw a core 5'! downwardly whereby to move a lever 58 about its fulcrum to cause the opposite end, which may be yoked in a suitable fashion and engages with a grooved collar 60, to move the upper plate of clutch i5 upwardly along the splined end of the shaft 14, compressing the spring !6 to stop driving the differential stub shaft ll. When this occurs the generator driven shaft 26 will stop since the rotation or the differential shaft 25 through the medium of the driven shaft 59 is dissipated in the free rotation of the now unloaded differential shaft H.

In the present specification an embodiment of the present invention has been shown and described as applied to a vehicle such as an automobile. However it will Joe-obvious that-the fun damental principles may readily be applied to any suitable power transmission mechanism such, for example, as a gun power drive or other drive mechanism wherein it is desired to effect a smooth and variable transmission of power.

While a particular embodiment of the invention is shown, it will be understood that it is not desired to be limited to the embodiment shown since many modifications may be made, and it is, therefore, contemplated by the appended claims to cover any such modifications as fall within the true spirit and scope of this bers including a magnetic clutch, a differential member connected between said driving and driven members, a current generating means for the magnetic clutch, said current generating means being driven by said differential member,

the differential member rotating the current 4 generating means at a speed which varies with the difference in relative rotation between the driving member and the driven member.

2. A variable speed power transmssicn comprising, a driving member, a driven member, means for interconnecting the driving member and the driven member for variable speed operation including a magnetic clutch, means for generating current for operation of the magnetic clutch, and means for varying the amount of current so generated in accord with the changes in relative speed of the driving and driven members.

3. A variable speed power transmission comprising, a driving member, a driven member, means for flexibly interconnecting the driving member and the driven member including a magnetic coupling, and a generator to provide electric current to the magnetic coupling, said generator being driven by a differential mechanism, a portion of the differential mechanism being connected to the driving member and another portion of the differential mechanism being connected to the driven member whereby relative rotation of the driving member with the driven member stationary will generate an electric current of high value and increased rotation of driven member will reduce the rate of relative rotation of the current generating means.

A variable speed power transmission comprising, a driving member, a driven member, an electromagnetic coupling between the driving and the driven members, a generator operably connected to the driving member and the driven member for rotation thereby, power combining means including a differential having :two rotat able members connected to the driving member the driven member respectively. and through a third rotatable member driving the generator to supply current to the electromagnetic coupling, and means for disconnecting the (inferential from 1e driving member.

5. .A variable speed power transmission comprising, a driving member, a driven member,

the driven member, a generator connected to said magnetic clutch means and having coupling means connecting it to the driving member, a direct drive coupling means between the driving member and the driven memben a centrifugal switch driven by the driven-member and a solenoid system energized by the centrifugal switch upon reaching a predetermined speed to disconnect one of said coupling means and connect the other.

6. A variable speed power transmission comprising driving and driven members, means providing a magnetic coupling between said members, a generator for supplying current to said means, a differential unit driven by said driving member and differentially connected to said generator and said driven member, and mechanism for uncoupling the generator from said driving member.

7. A variable speed power transmission com-'- prising driving and driven members, means providing a magnetic coupling between said members, a generator for supplying current to said means, mechanism for establishing a positive driving connection betweensaid members, means coupling said generator-to said driving member, and mechanism automatically responsive --to torque load on said driven member for simultaneously establishing said .positivedriving con- 6 nectlon and uncouplmg said generator from sald REFERENCES CITED drwing member.

8. In the apparatus of claim 7 a differential The following references are of record in the unit interposed between said driving member file Of this P n and said generator and also coupled to said UNITED STATES PATENTS driven member.

EDWQRD MAX ELL Number Name Date C w 1,451,465 Neuland Apr. 10, 1923 1,504,951 Hall Aug. 12, 1924 1,848,091 Winther Mar. 1, 1932 1,995,605 Downing Mar. 26', 1935 

